iLeakage: New Safari Exploit Impacts Apple iPhones and Macs with A- and M-Series CPUs

A group of academics has devised a novel side-channel attack dubbed iLeakage that exploits a weakness in the A- and M-series CPUs running on Apple iOS, iPadOS, and macOS devices, enabling the extraction of sensitive information from the Safari web browser. "An attacker can induce Safari to render an arbitrary webpage, subsequently recovering sensitive information present within it using

Zenbleed: How the quest for CPU performance could put your passwords at risk

You need to turn on a special setting to stop (the code you wrote to stop [the code you wrote to improve performance] from reducing performance) from reducing security.